1. Field of the Invention
The present invention relates to a base system for bus connection with a docking system and a method for controlling the same.
2. Background of the Related Art
As well known to those skilled in the art, a portable terminal that uses battery power for system power such as a personal digital assistant (PDA), an international mobile telecommunications (IMT)-2000 terminal, a personal communication service (PCS) terminal, personal computer and so forth, includes a plurality of devices. The plurality of devices can include, for example, a central processing unit (CPU), a random access memory (RAM), an audio module, a liquid crystal display (LCD) module, a communication module, etc.
The portable terminal (hereafter “base system”) further includes at least one expansion unit for function expansion through which an external system (hereafter “docking system”) can be docked to the base system as needed. The docking system is typically dockable to the base system via a bus interface predefined by a hardware logic, for example, an industry standard architecture (ISA) bus interface or a peripheral component interconnect (PCI) bus interface.
However, conflicts between the docking system and the base system when establishing an interface for functional expansion of the base system can prevent the interface and cause base system hang-ups. Accordingly, attempts to establish the interface must be repeated which reduce the base system availability and increase operator inconvenience.
FIG. 1 is a block diagram showing construction of a related art base system for improving bus connection with a docking system. As shown in FIG. 1, the base system 100 is connected with the docking system 150 via a docking PCI bus interface. The base system 100 includes a PCI bus controller 110, a PCI bus idle state detector 120 and a docking switch 130.
The PCI bus controller 110 recognizes a docking detection signal generated because of connection of the docking system 150 to the base system 100, and provides a PCI bus ready signal to the PCI bus idle state detector 120. In response to the PCI bus ready signal from the PCI bus controller 110, the PCI bus idle state detector 120 checks whether a PCI bus is currently in an idle state, and provides a docking PCI bus connection enable signal to the docking switch 130 if the PCI bus is in the idle state.
The docking switch 130 performs a switching operation in response to the PCI bus connection enable signal from the PCI bus idle state detector 120 to carry out the bus connection-based docking between the docking system 150 and the PCI bus controller 110 in the base system 100.
However, to accurately check the idle state of the PCI bus, which is an essential element for the docking between the related art base system and the docking system, the base system must have a hardware module for operating the base system at a higher speed than a clock frequency (i.e., 33 Khz) at which the PCI bus is operated, namely, a logic for checking the idle state of the PCI bus. The hardware module results in an increase in installation cost. Moreover, because the PCI bus instantaneously enters the idle state on an irregular time basis, as a practical matter, it is difficult to detect and generate the PCI bus connection enable signal at a point of time that the PCI bus enters the idle state. Further hardware logic checks to system idle state should be added to connect the docking system 150 with the base system 100, because it is difficult for the PCI bus idle state detector 120 to generate “dock PCI bus connect enable signal” by using software polling for the very short “idle state” period. Further, the PCI bus idle state checking logic has to include a separate hardware unit for inputting and outputting event information and status information to notify the base system that the docking bus connection has actually been successfully established.
Provided that the base system receives a docking connection event message resulting from a docking connection process from the docking system under the condition that it has no separate unit for inputting and outputting event information and status information, the base system will internally perform a docking configuration-based process by operating systems under the condition that a failure in its docking reprocessing operation occurs when it does not complete the docking bus connection with the docking system.
As described above, the related art base system has various disadvantages. The related art base system must additionally include the PCI bus idle state detection logic, which causes an increase in installation cost. Further, the related art base system still fails to establish the interface and cause the base system hang-up because the base system bus (e.g., PCI bus) status can change after being checked before interface establishment. In addition, not all base system buses are checked by the related art hardware module. Thus, the bus connection is difficult to make because of characteristics of the PCI bus.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.